Shelf unit



FIG. 1 is a front perspective view of a shelf unit;

FIG. 2 is another front perspective view thereof;

FIG. 3 is a bottom perspective view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

CLAIM The ornamental design for a shelf unit, as shown and described.